Vacuum induction casting plant without crucible



Aug. 12, 1969 v, GREG-N ETAL 3,460,608

VACUUM INDUCTION CASTING PLANT WITHOUT CRUCIBLE Filed March 4, 1966IV////// /////////////////)/fl///////l United States Patent 3,460,608VACUUM INDUCTION CASTING PLANT WITHOUT CRUCIBLE Vyacheslav PetrovichGrechin, Kutuzovsky prospekt 8, kv. 37; Zakllar Alexeevich Oreshmkov,Otkrytoe shosse 21, korpus 2, kv. 7; and Boris Fedorovlch Mrlyaev,Izmarlovsky Prospekt 117/1, kv. 17, all of Moscow, USSR.

Filed Mar. 4, 1966, Ser. No. 531,980 Int. Cl. B22d 27/02, 27/16 US. Cl.164-251 3 Claims ABSTRACT OF THE DISCLOSURE A plant for producingcastings by melting billets in which the billets are charged intochambers WhlCh are evacuated whereafter the billets from the chambersare supplied to respective heating means in a vacuum chamber in sequenceand therein melted and deposited as a continuous stream into a mold.

The present invention relates to apparatus for melting metal, and moreparticularly to vacuum lnduction plants without crucible for makingingots and castings of metal obtained by melting billets.

Known in the art are vacuum induction plants for making castings ofbillets, said plants being provided with an inductor for melting abillet without the use of a crucible and a mold for the molten metal. I

In these plants, upon melting a billet supplied into the meltinginductor, the stream of molten metal is interrupted until the followingbillet is supplied into the inductor. With such a melting procedure, itis difficult to obtain quality ingots of large weight.

As to the use of starting billets of a greater length and diameter, thisis impracticable on account of the difficulties involved in theproduction of such billets, especially of a difficult-to-machine metal.

An object of the present invention is to provide such a vacuum inductionplant without crucible which enables the manufacture of quality castingsof large weight from metal obtained by melting down small billetswithout interrupting the stream of metal.

According to this and other objects, the proposed vacuum induction plantwithout crucible, according to the invention, employs a plurality ofmelting inductors opcrating either alternately or simultaneously. Thereceiving chamber of the plant is preferably constructed as a pluralityof sections the number of which corresponds to the number of meltinginductors.

One of the possible embodiments of the proposed plant for making ingotsand castings from metal obtained by melting down billets is representedpartially in section in the sole figure of the attached drawing.

The vacuum induction plant without crucible is comprised of threeessential parts, namely: a melting chamber 1, chambers 2 for chargingbillets, and a chamber 3 for discharging an ingot or a cast piece.

The melting chamber 1 accommodates three melting inductors 4 suppliedwith electric current from high-frequency generators. An additionalinductor 5, supplied from the industrial mains, is employed forpreheating a mold 6 to mix preheat the molten metal contained in themold. The chambers 2 for charging billets are constituted as threeseparate sections (according to the number of melting inductors)connected with the melting chamber 1 by means of three vacuum locks 7(the drawing shows but one vacuum lock). Each section is essentially areceiver, into which can be simultaneously charged a plurality ofbillets according to their size and diameter. The billets 8 are chargedinto sections through doors 9.

Three mechanisms 10 are employed to effect the automatic supply of thebillets 8 into the melting inductors 4.

The discharging chamber 3 is isolated from the melting chamber 1 bymeans of a vacuum lock 11. This chamber accommodates a mechanism 12 forlifting and lowering the mold 6. In the case where an ingot is to becast into a water-cooled mold, the mechanism 12 functions as a means forextracting the ingot. The ingot or the molds are discharged from thechamber 3 through a door 13.

The vacuum plant of the invention operates as follows:

Each operation is started by lowering the mold 6, by means of themechanism 12, into the discharging chamber 3. A casting is removed fromthe mold and the latter is then raised into the melting chamber. Then,the billets 8 to be melted are charged into the chamber 2. Afterwards,the doors 9 and 13 are closed, and the air is evacuated from the plantuntil a residual pressure squal to 1 to 3 microns of mercury isobtained. Simultaneously, the neXt billet is supplied into one of themelting inductors 4; the metal melts and pours into the mold 6. Uponmelting down of the first billet, the next melting inductor with a newbillet is started, and the process of melting thus continues. At thesame time, the first melting inductor is prepared for the next heat,which is brought about by supplying the following billet into it.

As a result of the consecutive melting of billets supplied into thecorresponding melting inductors, the metal is poured in a continuousstream into the mold.

In the course of the heating, it is permissible for the vacuum in one ofthe chambers 2 to be disturbed, so that it can be charged with newbillets. As soon as the air is evacuated from this chamber, it becomesready for the continuation of operation.

Thus, the proposed vacuum induction plant can operate continuously for apractically unlimited period of time.

In case where it is required to pour into the mold a large volume ofmetal at once for the manufacture of a complicated casting or for makingan ingot of a large section, all the melting inductors 4 may be operatedsimutaneously. For this purpose, the billets are supplied into all theinductors, and the molten metal thus obtained is poured into the mold 6.

What is claimed is:

1. A plant for producing castings by melting metal prefabricatedbillets, said plant comprising: a vacuum chamber; melting meansaccommodated in said vacuum chamber, a mold for molten metal in saidvacuum chamber; a plurality of hermetically-sealed chambers mountedabove said vac-uum chamber each including receiving means foraccommodating billets to be melted; vacuum lock means connecting eachsaid hermetically-sealed chamber and said vacuum chamber such that thehermeticallysealed chambers can be selectively isolated from the vacuumchamber; means for transferring the billets from the hermetically-sealedchambers through a respective vacuum lock means into said melting meansin said vacuum chamber, said melting means being positioned above saidmold whereby molten metal from the melting means is deposited into themold and a finished ingot is cast in said mold, and means fordischarging finished ingots from said vacuum chamber.

2. A plant as claimed in claim 1, wherein a separate melting means isprovided in said vacuum chamber for each hermetically-sealed chamber.

3. A plant as claimed in claim 2, wherein said vacuum lock means isoperative to isolate successive receiver means from the vacuum chamberto enable their supply with billets while the other receiver meanscontinue to 3 supply billets to their respective heating means wherebycontinuous supply of molten material to the mold is effected.

References Cited UNITED STATES PATENTS 2,445,670 7/1948 Hopkins 164-2522,686,864 8/1954 Wroughton et al. 164-65 XR 2,818,461 12/1957 Gruber eta1. 164-252 XR 4 3,014,255 12/1961 Bussard et a1. 164251 XR 3,234,6082/1966 Peras l6452 3,226,102 12/1965 Pagonis 16465 X J. SPENCEROVERHOLSER, Primary Examiner R. SPENCER ANNEAR, Assistant Examiner US.Cl. X.R. 16465, 258

